The present invention generally relates to a control pedal for a motor vehicle and, more particularly, to a control system for selectively adjusting the control pedal to desired positions.
Control pedals are typically provided in a motor vehicle, such as an automobile, which are foot operated by the driver. Separate control pedals are provided for operating brakes and an engine throttle. When the motor vehicle has a manual transmission, a third control pedal is provided for operating a transmission clutch. A front seat of the motor vehicle is typically mounted on tracks so that the seat is forwardly and rearwardly adjustable along the tracks to a plurality of positions so that the driver can adjust the front seat to the most advantageous position for working the control pedals.
This adjustment method of moving the front seat along the tracks generally fills the need to accommodate drivers of various size, but it raises several concerns. First, this adjustment method still may not accommodate all drivers due to very wide differences in anatomical dimensions of drivers. Second, the position of the seat may be uncomfortable for some drivers. Therefore, it is desirable to have an additional or alternate adjustment method to accommodate drivers of various size.
Many proposals have been made to selectively adjust the position of the control pedals relative to the steering wheel and the front seat in order to accommodate drivers of various size. For example, U.S. Pat. Nos. 5,632,183, 5,697,260, 5,722,302, 5,819,593, 5,937,707, and 5,964,125, the disclosures of which are expressly incorporated herein in their entirety by reference, each disclose an adjustable control pedal assembly. The control pedal assembly includes a hollow guide tube, a rotatable screw shaft coaxially extending within the guide tube, a nut in threaded engagement with the screw shaft and slidable within the guide tube, and a control pedal rigidly connected to the nut. The control pedal is moved forward and rearward when an electric motor rotates the screw shaft to translate the nut along the screw shaft within the guide tube. A potentiometer is provided at the motor which sends signals to a CPU regarding motor shaft position for determining the position of the nut. While this control pedal assembly may adequately adjust the position of the control pedal to accommodate drivers of various size, this control pedal may be prone to undetected failures. Accordingly, there is a need in the art for an adjustable control pedal assembly which selectively adjusts the position of the pedal to accommodate drivers of various size, is relatively simple and inexpensive to produce, and is highly reliable in operation.
The present invention provides a control system for an adjustable control pedal which overcomes at least some of the above-noted problems of the related art. According to the present invention, a control pedal includes a first support, a screw secured to the first support, a nut threadably engaging the screw and adapted to move axially along the screw upon rotation of the screw, and a motor operatively connected to the screw to selectively rotate the screw. A second support carries a pedal at a lower end and is operatively connected to the nut for fore-aft movement of the second support relative to the first support upon axial movement of the nut along the screw. A control system includes a sensor located near the screw and adapted to sense rotations of the screw and a controller in communication with the sensor to receive signals from the sensor. With the sensor located near the screw, rotation of the screw can be directly determined from the sensor.
According to another aspect of the present invention, a control includes a first support, a screw secured to the first support, a nut threadably engaging the screw and adapted to move axially along the screw upon rotation of the screw, and a motor operatively connected to the screw to rotate the screw and axially move the nut along the screw in response to rotation of the screw. A second support carries a pedal and is operatively connected to the nut for fore-aft movement of the second support relative to the first support
upon axial movement of the nut along the screw. The control pedal also includes a sensor and a controller in communication with the sensor to receive signals from the sensor. The controller is adapted to determine a position of the nut along the screw based on signals from the sensor and to automatically stop the motor when the nut reaches a predetermined end of travel for the nut along the screw. By utilizing electronic or xe2x80x9csoftxe2x80x9d stops rather than engaging mechanical or xe2x80x9chardxe2x80x9d stops at the ends of travel, undesired stress on the motor and premature failure of the motor can be prevented.
According to yet another aspect of the present invention, a control pedal includes a first support, a screw secured to the first support, a nut threadably engaging the screw and adapted to move axially along the screw upon rotation of the screw, and a motor operatively connected to the screw to selectively rotate the screw and axially move the nut along the screw in response to the rotation of the screw. A second support carries a pedal and is operatively connected to the nut for fore-aft movement of the second support relative to the first support upon axial movement of the nut along the screw. The control pedal further includes a sensor and a controller in communication with the sensor to receive signals from the sensor. The controller is adapted to automatically stop the motor when signals from the sensor indicate that the screw is not rotating. An early detection of a failure in the mechanical system allows the pedal assembly to be xe2x80x9cshut downxe2x80x9d to prevent damage or further damage to the system
According to even yet another aspect of the present invention, a control pedal assembly includes first and second control pedals Each control pedal includes a first support, a screw secured to the first support, and a nut threadably engaging the screw. Each control pedal also includes a second support carrying a pedal and operatively connected to the nut for fore-aft movement of the second support relative to the first support upon axial movement of the nut along of the screw. A control system includes at least one motor operatively connected to the screws to selectively rotate the screws and axially move the nuts along the screws in response to rotation of the screws, a sensor located near the screw of the first control pedal and adapted to sense rotation of the screw of the first control pedal, and a controller in communication with the sensor to receive signals from the sensor. In one embodiment the screws are connected in series with the motor and the sensor is located near the last screws so that a single sensor is required to indicate failure anywhere along the drive chain. In another embodiment, a second sensor is located at the screw of the second control pedal. This embodiment is particularly advantageous to automatically stop the motor when positions of the nuts indicate that a predetermined fore-aft relationship between the pedals has not been maintained. An example of such a predetermined fore-aft relationship is the rearward positioning of an accelerator pedal relative to a brake pedal which is typically referred to as step over. Early detection of a change in the predetermined relationship between the two control pedals allows the control pedal assembly to be xe2x80x9cshut downxe2x80x9d to minimize the change in the predetermined relationship between the control pedals.
According to even yet another aspect of the present invention, a control pedal includes a first support, a screw secured to the first support, a nut threadably engaging the screw and adapted to axially move along the screw upon rotation of the screw; and a motor operatively connected to the screw to selectively rotate the screw and axially move the nut along the screw. A second support carries a pedal and is operatively connected to the nut for fore-aft movement of the second support relative to the first support upon axial movement of the nut along the screw. A controller is in communication with the motor and is adapted to automatically operate the motor to move the second support in a forward direction relative to the first support to a predetermined position when predetermined conditions are met. By Automatically moving the control pedal forward when the predetermined conditions indicate the driver is about to egress the motor vehicle, the driver is provided additional leg room to egress the vehicle and the next driver has additional room to ingress the vehicle.
According to even yet another aspect of the present invention, a control pedal assembly includes a first support, a screw secured to the first support, a nut threadably engaging the screw and adapted to axially move along the screw upon rotation of the screw, and a motor operatively connected to the screw to selectively rotate the screw and axially move the nut along the screw. A second support carries a pedal and is operatively connected to the nut for fore-aft movement of the second support relative to the first support upon axial movement of the nut along the screw. A control system includes a lock-out switch adapted to be manually engaged and a controller which operatively connects the lock-out switch and the motor to prevent movement of the second support relative to the first support when the lock-out switch is engaged. The lock-out switch enables the driver to prevent undesired or accidental movement of the control pedal.
From the foregoing disclosure and the following more detailed description of various preferred embodiments it will be apparent to those skilled in the art that the present invention provides a significant advance in the technology and art of control pedal assemblies. Particularly significant in this regard is the potential the invention affords for providing a high quality, feature-rich, low cost assembly. Additional features and advantages of various preferred embodiments will be better understood in view of the detailed description provided below.